Reversible bistability of conductance on graphene/CuOx/Cu nanojunction

We report that a nanojunction composed of graphene, copper oxide, and Cu substrate exhibits resistive switching behavior, revealed with conductive probe atomic force microscopy at ultrahigh vacuum. The current-voltage curve measured between the titanium nitride-coated tip and the nanojunction exhibited reversible bistable resistance states. We propose that the switching behavior is controlled by the migration of oxygen ions in the copper oxide layer, leading to the reversible formation/disruption of a CuOx-associated charge tunneling barrier, which is consistent with glancing-angle x-ray photoelectron spectroscopy analysis. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3694754]